Search

Proton inelastic scattering off a neutron halo nucleus, 11 Li, has been studied in inverse kinematics at the IRIS facility at TRIUMF. The aim was to establish a soft dipole resonance and to obtain its dipole strength. Using a high quality 66 MeV 11 Li beam, a strongly populated excited state in 11 Li was observed at E x = 0.80 ± 0.02 MeV with a width of Γ = 1.15 ± 0.06 MeV . A DWBA (distorted-wave Born approximation) analysis of the measured differential cross section with isoscalar macroscopic form factors leads us to conclude that this observed state is excited in an electric dipole (E1) transition. Under the assumption of isoscalar E1 transitions, the strength is evaluated to be extremely large amounting to 30 ∼ 296 Weisskopf units, exhausting 2.2 % ∼ 21 % of the isoscalar E1 energy-weighted sum rule (EWSR) value. The large observed strength originates from the halo and is consistent with the simple di-neutron model of 11 Li halo. [ABSTRACT FROM AUTHOR]

The β-decay half-lives of 128-130Cd have been measured with the newly commissioned GRIFFIN γ-ray spectrometer at the TRIUMF-ISAC facility. The time structures of the most intense γ rays emitted following the β decay were used to determine the half-lives of 128Cd and 130Cd to be T1/2=246.2(21) ms and T1/2=126(4) ms, respectively. The half-lives of the 3/2+ and 11/2− states of Cd129 were measured to be T1/2(3/2+)=157(8) ms and T1/2(11/2-)=147(3) ms. The half-lives of the Cd isotopes around the N=82 shell closure are an important ingredient in astrophysical simulations to derive the magnitude of the second r-process abundance peak in the A∼130 region. Our new results are compared with recent literature values and theoretical calculations. [ABSTRACT FROM AUTHOR]